研究顯示：做家務(wù)能練出纖纖細(xì)腰

One reason so many American women are overweight may be that we are vacuuming and doing laundry less often, according to a new study that, while scrupulously even-handed, is likely to stir controversy and emotions.

一項(xiàng)新的研究顯示，美國(guó)有如此之多的超重女性，原因之一是她們不再那么經(jīng)常使用吸塵器和洗衣服。即使以謹(jǐn)慎而公正的方式進(jìn)行，這項(xiàng)研究也可能在輿論和情感層面引起軒然大波。

The study, published this month in PLoS One, is a follow-up to an influential 2011 report which used data from the U.S. Bureau of Labor Statistics to determine that, during the past 50 years, most American workers began sitting down on the job. Physical activity at work, such as walking or lifting, almost vanished, according to the data, with workers now spending most of their time seated before a computer or talking on the phone. Consequently, the authors found, the average American worker was burning almost 150 fewer calories daily at work than his or her employed parents had, a change that had materially contributed to the rise in obesity during the same time frame, especially among men, the authors concluded.

上述研究成果是2011年發(fā)表的一篇論文的續(xù)作，刊登在本月的科研雜志《PLoS One》上。前作引起了很大反響，它通過(guò)美國(guó)勞工統(tǒng)計(jì)局(Bureau of Labor Statistics)的數(shù)據(jù)得出結(jié)論說(shuō)，50年來(lái)，大多數(shù)美國(guó)勞動(dòng)者逐漸開(kāi)始坐著工作。像四處走動(dòng)或搬運(yùn)東西這樣的體力勞動(dòng)幾乎已經(jīng)消失。這些數(shù)據(jù)顯示，現(xiàn)在勞動(dòng)者把大多數(shù)時(shí)間都用在了操作電腦和打電話上。該論文的作者發(fā)現(xiàn)，和他們的父輩相比，美國(guó)勞動(dòng)者每天在工作中消耗的熱量減少了150大卡。作者斷定，這樣的變化對(duì)同一時(shí)期肥胖現(xiàn)象的增多有實(shí)質(zhì)性的推動(dòng)作用，特別是男性肥胖。

“Fifty years ago, a majority of women did not work outside of the home, ” said Edward Archer, a research fellow with the Arnold School of Public Health at the University of South Carolina in Columbia, and lead author of the new study.

哥倫比亞市南卡羅來(lái)那大學(xué)阿諾德公共健康學(xué)院(Arnold School of Public Health at University of South Carolina)研究員愛(ài)德華·阿徹(Edward Archer)博士是這篇新研究報(bào)告的主筆。他說(shuō)：“50年前，多數(shù)女性都不外出工作。”

So, in collaboration with many of the authors of the earlier study of occupational physical activity, Dr. Archer set out to find data about how women had once spent their hours at home and whether and how their patterns of movement had changed over the years.

因此，阿徹博士聯(lián)合了在之前的論文中探討過(guò)職業(yè)體力勞動(dòng)情況的多位作者，開(kāi)始著手尋找過(guò)去女性在家中分配時(shí)間的數(shù)據(jù)，進(jìn)而探究這些年來(lái)她們的行為模式是否改變以及出現(xiàn)了哪些變化。

He found the information he needed in the American Heritage Time Use Study, a remarkable archive of “time-use diaries” provided by thousands of women beginning in 1965. Because Dr. Archer wished to examine how women in a variety of circumstances spent their time around the house, he gathered diaries from both working and non-employed women, starting with those in 1965 and extending through 2010.

他在一項(xiàng)名為“美國(guó)時(shí)間分配研究資料庫(kù)”(American Heritage Time Use Study, AHTUS)的研究中找到了自己需要的信息。AHTUS的課題是美國(guó)人怎樣利用時(shí)間，它有一個(gè)非同凡響的數(shù)據(jù)庫(kù)，其中收集了從1965年至今數(shù)千名美國(guó)女性的日記，內(nèi)容是自己如何分配時(shí)間。由于阿徹博士希望了解不同條件下美國(guó)女性怎樣在家里支配時(shí)間，所以他同時(shí)收集了職業(yè)女性和家庭主婦的日記，這些日記從1965年開(kāi)始，一直延續(xù)到2010年。

He and his colleagues then pulled data from the diaries about how many hours the women were spending in various activities, how many calories they likely were expending in each of those tasks, and how the activities and associated energy expenditures changed over the years.

接下來(lái)，阿徹博士和同事們開(kāi)始從這些日記中提取信息，以確定美國(guó)女性在各項(xiàng)家務(wù)上花費(fèi)的時(shí)間、消耗的熱量以及這么多年來(lái)這些家務(wù)和與之相關(guān)的能量消耗有了怎樣的變化。

As it turned out, their findings broadly echoed those of the occupational time-use study. Women, they found, once had been quite physically active around the house, spending, in 1965, an average of 25.7 hours a week cleaning, cooking and doing laundry. Those activities, whatever their social freight, required the expenditure of considerable energy. (The authors did not include child care time in their calculations, since the women’s diary entries related to child care were inconsistent and often overlapped those of other activities.) In general at that time, working women devoted somewhat fewer hours to housework, while those not employed outside the home spent more.

最終，他們的發(fā)現(xiàn)和此前對(duì)勞動(dòng)者如何分配時(shí)間的研究所得出的結(jié)論大體相同。以前，美國(guó)女性曾在家中從事相當(dāng)多的體力勞動(dòng)。在1965年，她們花在清掃、做飯和洗衣服上的時(shí)間平均為每周25.7個(gè)小時(shí)。無(wú)論借助怎樣的工具，這些家務(wù)都會(huì)消耗相當(dāng)多的能量。(研究者們沒(méi)有把照看孩子的時(shí)間計(jì)算在內(nèi)，原因是這些女性在照看孩子方面的記錄存在矛盾而且經(jīng)常和其他家務(wù)重疊在一起。)總的來(lái)說(shuō)，當(dāng)時(shí)職業(yè)女性在家務(wù)上花的時(shí)間較少，而家庭主婦在這方面所花的時(shí)間則較多。

Forty-five years later, in 2010, things had changed dramatically. By then, the time-use diaries showed, women were spending an average of 13.3 hours per week on housework.

45年后，也就是2010年，情況有了顯著變化。上述日記顯示，到2010年，美國(guó)女性花在家務(wù)上的時(shí)間平均為每周13.3小時(shí)。

More striking, the diary entries showed, women at home were now spending far more hours sitting in front of a screen. In 1965, women typically had spent about eight hours a week sitting and watching television. (Home computers weren’t invented yet.)

更引人注目的是，在這些日記中，家庭主婦坐在電視或電腦前的時(shí)間大幅上升。1965年，美國(guó)女性每周看電視的時(shí)間通常為八小時(shí)左右(當(dāng)時(shí)還沒(méi)有出現(xiàn)家用電腦)。

By 2010, those hours had more than doubled, to 16.5 hours per week. In essence, women had exchanged time spent in active pursuits, like vacuuming, for time spent being sedentary.

到了2010年，這個(gè)數(shù)字提高了一倍以上，達(dá)到每周16.5小時(shí)。實(shí)際上，美國(guó)女性壓縮了用在清掃等動(dòng)態(tài)行為上的時(shí)間，而延長(zhǎng)了靜坐不動(dòng)的時(shí)間。

In the process, they had also greatly reduced the number of calories that they typically expended during their hours at home. According to the authors’ calculations, American women not employed outside the home were burning about 360 fewer calories every day in 2010 than they had in 1965, with working women burning about 132 fewer calories at home each day in 2010 than in 1965.

在這個(gè)過(guò)程中，她們?cè)诩依锵牡臒崃肯陆盗撕芏?。研究者們?jì)算，2010年美國(guó)家庭主婦每天消耗的熱量比1965年減少了360大卡左右，對(duì)職業(yè)女性來(lái)說(shuō)，這個(gè)數(shù)字約為132大卡。

“Those are large reductions in energy expenditure, ” Dr. Archer said, and would result, over the years, in significant weight gain without reductions in caloric intake.

阿徹博士指出：“這在能量消耗方面是一個(gè)巨大退步。”如果不減少熱量攝入，長(zhǎng)此以往體重就會(huì)明顯上升。

This does not mean, he said, that women — or men — should be doing more housework. For one thing, the effort involved is such activities today is less than it once was. Using modern, gliding vacuum cleaners is less taxing than struggling with the clunky, heavy machines once available, and thank goodness for that.

他說(shuō)這并不意味著女性或男性應(yīng)該分擔(dān)更多家務(wù)。首先，現(xiàn)在做家務(wù)已不像從前那樣耗費(fèi)體力。謝天謝地，如今的吸塵器輕巧靈活，不像以前那樣笨拙沉重，使用起來(lái)也不再那么費(fèi)力。

Nor is more time spent helping around the house a guarantee of more activity, over all. A telling 2012 study of television viewing habits found that when men increased the number of hours they spent on housework, they also greatly increased the hours they spent sitting in front of the TV, presumably because it was there and beckoning.

其次，總的來(lái)說(shuō)在家務(wù)上花更多時(shí)間并不能保證有更多的運(yùn)動(dòng)量。2012年一項(xiàng)關(guān)于看電視習(xí)慣的研究就生動(dòng)地說(shuō)明了這一點(diǎn)。這項(xiàng)研究表明，人們做家務(wù)的時(shí)間增多后，他們坐在那里看電視的時(shí)間也會(huì)大幅上升，原因大概是開(kāi)著的電視引起了他們的注意。

Instead, Dr. Archer said, we should start consciously tracking what we do when we are at home and try to reduce the amount of time spent sitting. “Walk to the mailbox, ” he said. Chop vegetables in the kitchen. Play ball with your, or a neighbor’s, dog. Chivvy your spouse into helping you fold sheets. “The data clearly shows, ” Dr. Archer said, that even at home, we need to be in motion.

阿徹博士說(shuō)，相反，人們待在家里時(shí)應(yīng)該有意識(shí)地記錄自己的活動(dòng)并設(shè)法縮短坐著的時(shí)間。他建議說(shuō)：“走到信箱那兒取信”，到廚房切菜，和自己或者鄰居養(yǎng)的狗做游戲，哄愛(ài)人幫你一起疊床單。他指出，“這些數(shù)據(jù)清楚地表明”，就算在家，我們也需要?jiǎng)悠饋?lái)。